As the settling process continues, a sludge forms at the bottom of whatever is holding the wastewater. As part of the wastewater treatment process, this sludge accumulates in:
- Settling ponds
- Sludge ponds
- Clarifiers
- Thickeners
Once the sludge forms, companies, and municipalities can manage and dispose of it through different methods.
Organizations do not use coagulants and flocculants to make sediment fall out of liquid suspension. Due to their ability to neutralize and agglomerate colloids, the chemicals also support dissolved air flotation (DAF) applications. In DAF applications, microbubbles pull the solids to the top of a tank, where a skimmer removes them.
Northstar’s Polymer Services
Whatever the application, a Northstar representative can help you find the best chemistry to achieve your performance goals at the lowest overall cost with the lowest amount of operator interface required.
Polymers play an important role in wastewater treatment. Besides separating solids from liquids, they also help thicken sludge and dewater contaminated material for easier handling and disposal.
Removing the water content from a waste sludge can change the waste properties from liquid to solid waste. This change has significant impacts on the disposal cost or tipping fee.
The Industry Standard for Solid vs Liquid Waste
The industry standard determining whether the waste is solid or liquid is EPA Method 9095B or “the paint filter test.” In this procedure, the tester places a sample of the waste sludge in a standard 60-mesh conical paint filter for 5 minutes.
If no liquid passes through the filter, the tester deems the waste solid and the organization can dispose of it more cost-effectively than liquid waste. In the industry, we would consider sludge passing the paint filter test to be dewatered.
Polymer flocculants expedite the dewatering processing by allowing water to leave the flocculated solids more freely.
Industries That Use Polymers to Treat Wastewater
Almost any industry that needs to remove solids from their wastewater stream can use polymers in their treatment process.
Aggregate producers use water to wash the sand, gravel, or other aggregates they produce. The wash water picks up dirt, clay, and silt during the washing process. To reuse or safely discharge this wash water, organizations must separate the solids from the water.
Many aggregate producers use settling ponds to hold the wastewater and allow sedimentation. As we noted, it can take a long time for sediment to fall out of liquid suspension.
Aggregate producers must stop production while cleaning their ponds and waiting for clean water. These shutdowns cause producers to lose production hours and increase labor hours.
However, polymers can increase the rate of sedimentation for aggregate producers. By using a polymer dosing system, producers can inject the polymer solution directly into their settling ponds.
The polymer dosing allows for easier management and disposal by:
- Increasing the sedimentation rate
- Providing clean water
- Thickening the sludge at the pond’s bottom
Polymer Use in Wastewater Prep
Many operations also use polymers to prepare wastewater before the operation mechanically treats the wastewater in:
- Clarifiers
- Thickeners
- Filter presses
- Centrifuges
- Other dewatering equipment
It’s important to note that not all wastewater treatment polymers are the same.
Northstar’s Custom Service for Wastewater Treatment
Northstar field technicians select specific chemistry for your unique process depending on your organization’s wastewater and operation needs.
Between the hundreds of different polymers available and the different make-down and feed systems for dry and emulsion polymers, it can be tough to know what is best for your application.
Your Northstar representative will provide the option(s) that best fit your needs and use jar testing to determine the best polymer chemistry. The right type of polymer will help you meet regulations, save money, and increase your operation’s success.
Northstar’s proprietary polymer controller helps you remove the need for constant operator adjustments while reducing your chemical costs and improving your system’s performance.
The polymers provided by Northstar Chemical meet the following certifications:
FDA, USDA, Kosher, Halal, non-GMO, GRAS, and NSF
For more information, visit our certifications page.
